Purpose: To evaluate the changes in electrooculography (EOG) after photodynamic therapy (PDT). Methods: Thirty-eight eyes of 38 patients (21 males, 17 females) with choroidal neovascularization secondary to age related macular degeneration were included in this study. Standart PDT with verteporfin was performed on each patient. Serial EOG recordings were performed before, 1 week, and 1 month after PDT. Results: Mean age of the patients was 69.8 +/- 9.7 years (range 56 and 90 years). Seven days after PDT the visual acuity improved in 17 eyes, remained unchanged in 16 eyes and deteriorated in 5 eyes. One month after PDT the visual acuity findings were the same as the first week. New hemorrhages were seen in three eyes in the first week after PDT and visual acuity was decreased in those patients. No other patient complained of ocular and systemic adverse events. There was a statistically significant reduction in the Arden ratio of the EOG 1 week after PDT and the reduction persisted in the first month recordings. Conclusions: The reduction in Arden ratio of EOG findings may indicate that retina pigment epithelium function could be affected after PDT.